The market for pre-owned chic bags and clothes has surged over the last three years, driven by younger, more environmentally conscious shoppers looking for affordable high-end goods. The market is expected to reach 33 billion euros ($37.2 billion) in size this year after growing by 65% between 2017 and 2021, according to consultancy Bain. This compares with 12% growth for brand new luxury goods.

Some rival luxury companies are already exploring the sector. Earlier this year, French conglomerate Kering (PRTP.PA) took a 5% stake in Vestiaire Collective, a leading platform for second-hand clothes and handbags. Kering's star brand Gucci also formed a partnership with U.S.-based resale platform The RealReal (REAL.O) last year.

"It can be a partnership with a player or it can be something more in-house, or both of them, a sort of hybrid solution like for e-commerce," Bertelli said.

The heir to Prada's empire, said he wants to keep the family-controlled group independent when he takes the reins in a few years, doesn't seem fazed by the future challenges of the ever-changing luxury sector.